Shielding device



Dec. 8, 1936. M BOWMAN 2,063,786

SHIELDING DEVICE Filed Feb. 27, 1935 Patented Dec. 8, 1936 John M.Bowman,

Application February 2'1,

This invention relates to electrical apparatus.

STATES PATENT OFFICE 2,063,786 SHIELDING DEVICE Philadelphia, Pa.,assignor to Philco Radio & Television Corporation, Philadelphia, Pa., acorporation of Delaware 4 Claims.

shielding devices for More specifically the invention relates toshielding devices for vacuum tubes of radio receivers.

One object of the invention is to provide a device Which is which isefiicient the vacuum tube easy and economical to ture, particularly inquantity production, andin operation and serves to hold firmly, thuspreventing micromanufacphonic action of the tube due to vibration.

Another object of the invention is to provide a device which may appliedto a vacuum be easily manipulated and tube even though there,

may be some mismatch of the elements.

A further object of the vide a device composed of constructed so thatattached together regardl thereof and which assures tact of the parts.

invention is to proa plurality of parts the parts may be properly ess ofslight misfit good electrical conof the device is illustrated indrawing, wherein Fig. l is an elevational view of the lid of the device;

Fig. 2 isan elevational view of the shell;

Fig. 3 is an elevational v iew of the base;

Fig. 4 is a plan view of the base;

Fig. 5 is an elevational section of the device in cooperative relationwith a vacuum tube; and

Fig. 6 is a sectional view along line 6-6 of Fig. 4.

Referring to a body or shell I,

the drawing the device comprises a lid 2, and a base 3. These parts maybe made of terneplate or any other a material which is satisfactory. Thebody I is substantially or generally square in cross-section withrounded corners. ventional manner from a The four corners It may be madein confiat piece of material. at the bottom of the body are slightlyflared outward, as at 4, and this together with the deformability ofplacing it on the base eve be some slight misfit. A

the body facilitates n though there may small rim 5 may be formed at thebottom of the body to stiffen it and make it fit tightly over the base.

Preferably, there are small centrally located holes 6 in the sides ofthe body to provide venin place, as shown at I in cross-sectional areaof the the tube fits snugly therein tion of the glass envelope Figs. 5and 6. The body I is such that with the widest por- 8 of the tube seated1935, Serial No. 8,577

in the openings of thebody, as shown in Fig. 6. This serves to hold thetube securely and prevents vibration or rattling of the same with itsconsequent microphonic action. Due to the deformability of the bodypermitted by its square cross-sectional form, it adjusts itself to thetube when necessary thereby assuring the desired tight fit.

The body I may be provided with a recess or slot 9 to allow entrance ofa conductor attached to the grid terminal at the top of the tube. Asmall ridge Il may be indented around the top of the body to hold thelid or cover firmly in place. The top edge of the body is preferablyturned over, as at H to eliminate sharp exposed edges. The lid 2 may beformed of extruded terneplate and is adapted to fit snugly over the topof the body I. It is not essential, however, that a lid be used.

The base 3 may also be extruded from terneplate. This member is of thesame contour as the body and is adapted to fit snugly inside the lowerpart of the body, as shown in Fig. 5. The base is provided with roundedcorners and has diagonally opposite corner indentations l3 to provideapertured mounting ears M. These, corner indentations also provide spacewhich allows for mismatch between the body and base. The large aperturel of the base is adapted tov receive the base I6 of the vacuum tube. Therim formed by the hole IS in the base serves to stiffen the base andthus hold the shell I in place. This tight fit also provides goodelectrical contact between the shell and the base, thus assuring thatthe metal shell will act as an effective electrical shield.

Various changes or modifications are of course possible and are to bedeemed within the scope of the invention.

I claim:

1. A shielding device for electrical apparatus, such as vacuum tubes,comprising a relatively rigid metallic base of non-circularcross-section having corner indentations, and a body or shell of similarcross-section adapted to fit over said base and formed of deformablemetallic material, so that said shell fits snugly over the apparatuswith which it is used and also fits snugly over said. basenotwithstanding slight misfit of the said elements, said indentationsproviding space which permits greater deformability of said shell infitting over said base.

2. A shielding device for electrical apparatus, such as vacuum tubes,comprising a relatively rigid metallic base of non-circularcross-section having opposed corner indentations and means at saidindentations for mounting said base, and a body or shell of similarcross-section adapted to fit over said base and formed of deformablemetallic material, so that said shell fits snugly over the apparatuswith which it is used and also fits snugly over said basenotwithstanding slight misfit of the said elements, said indentationsproviding space which permits greater deformability of said shell infitting over said base.

3. A shielding device for electrical apparatus, such as vacuum tubes,comprising a relatively rigid metallic base of generally squarecross-section having rounded corners with opposed corner indentationsand means at said indentations for mounting said base, and a body orshell of similar cross-section having rounded and flared corners,adapted to fit over said base and formed of deformable metallicmaterial, so that said shell fits snugly over the apparatus with whichit is used and also fits snugly over said base notwithstanding slightmisfit of the said elements, said indentations providing space whichpermits greater deformability of said shell in fitting over said base.

4. A shielding device for a vacuum tube, comprising a relatively rigidmetallic base of generally square cross-section and having an openingfor reception of the tube base, said base having opposed cornerindentations and means at said indentations for mounting said base, anda metallic shell of similar cross-section deformable throughout itslength and adapted to fit over said base and having openings in itssides to seat the widest portion of the tube, so that said shell fitssnugly over the tube and also fits snugly over said base notwithstandingslight misfit of the said elements, said indentations providing spacewhich permits greater deformability of said shell in fitting over saidbase.

JOHN M. BOWMAN.

